Anisotropic Material Damage Model of Randomly Oriented Thermoplastic Composites for Crash Simulation

2020 ◽  
Author(s):  
Seiji Hayashi ◽  
Mitsuharu Kan ◽  
Kei Saito ◽  
Masato Nishi
Keyword(s):  
Anisotropic Material ◽  
Damage Model ◽  
Thermoplastic Composites ◽  
Material Damage ◽  
Crash Simulation

scholarly journals An Application of Bi-Directional Evolutionary Structural Optimisation for Optimising Energy Absorbing Structures Using a Material Damage Model

2014 ◽  
Vol 553 ◽  
pp. 836-841 ◽  
Author(s):  
Daniel Stojanov ◽  
Brian G. Falzon ◽  
Xin Hua Wu ◽  
Wen Yi Yan
Keyword(s):  
Finite Element ◽  
Damage Model ◽  
Ductile Material ◽  
Topology Optimisation ◽  
Material Damage ◽  
Structural Optimisation ◽  
Element Analysis ◽  
Element Mesh ◽  
Beso Method ◽  
Energy Absorbing

The Bi-directional Evolutionary Structural Optimisation (BESO) method is a numerical topology optimisation method developed for use in finite element analysis. This paper presents a particular application of the BESO method to optimise the energy absorbing capability of metallic structures. The optimisation objective is to evolve a structural geometry of minimum mass while ensuring that the kinetic energy of an impacting projectile is reduced to a level which prevents perforation. Individual elements in a finite element mesh are deleted when a prescribed damage criterion is exceeded. An energy absorbing structure subjected to projectile impact will fail once the level of damage results in a critical perforation size. It is therefore necessary to constrain an optimisation algorithm from producing such candidate solutions. An algorithm to detect perforation was implemented within a BESO framework which incorporated a ductile material damage model.

FEA Simulation of Clinching Process Based on GTN Damage Model

2013 ◽  
Vol 652-654 ◽  
pp. 2254-2260 ◽  
Author(s):  
Bai Jun Shi ◽  
Shu Hui Liao ◽  
Song Peng ◽  
Hang Li
Keyword(s):  
Simulation Model ◽  
Sheet Material ◽  
Damage Model ◽  
Model Parameters ◽  
Material Damage ◽  
Gtn Damage Model ◽  
Fea Simulation ◽  
Simulation Results ◽  
Clinch Joining ◽  
Joining Process

In this work, the Gurson-Tvergaard-Needleman (GTN) damage model is adopted to depict the material damage during the clinch joining process in a simulation-based theoretical model. The parameters of the GTN model which influence the void nucleation, growth and coalescence are identified. Their values of a specific material, C45E4 (ISO) steel, have been determined after carefully comparing the simulation results with the real sheet material tensile test. The established GTN damage model parameters are then imported into the simulation model to investigate the material damage during the mechanical clinch joining process. The Finite Element Analysis (FEA) simulation results show promising, because the material’s initial damage position can be located and analyzed. For a given design, the initial fracture point was predicted which is located on the inner side of the clinched joint neck of the upper sheet, which matches with the results of the experimental test very well. It can be concluded that the incorporation of GTN damage model has extend the capability of the simulation model.

scholarly journals Constitutive Modelling for Anisotropic Damage in Woven E-Glass Reinforcements

2017 ◽  
Vol 11 (1) ◽  
pp. 9-21
Author(s):  
Ping Yang ◽  
Ying Tong
Keyword(s):  
Composite Laminates ◽  
Damage Model ◽  
Fixed Time ◽  
Constitutive Modelling ◽  
Anisotropic Damage ◽  
Material Damage ◽  
Lower Velocity ◽  
Damage Area ◽  
Gfrp Composite ◽  
Damage Process

It is easy for composite laminates to be damaged by relative lower velocity impact which could give rise to internal delamination that will strongly weaken the compressive strength of laminates. In order to predict the occurrence of matrix failure, the elastic-brittle behaviors of fiber-reinforced composites were modeled constitutively by an anisotropic damage model. The dynamic tensile testing was performed at a constant velocity of 2 mm/min until the sample broke to achieve the mechanical parameters of E-glass reinforcements. The elastic constitutive equation and the constitutive damage model were obtained on basis of the fundamental theory of mechanics about the orthotropic constitutive of reinforcements. The methodology for this constitutive model which is developed by Hashin considered both the effect of fiber and matrix failure. Then, the developed constitutive equations were incorporated into the FE (finite element) codes, ABAQUS, through the user subroutine module to simulate the process of projectile impacting GFRP composite laminates. The results show that the material deformation reaches a maximum at 24 μs, then occurs rebound with the increase of the time. The stress of reinforcements traverse section linearly increases outward from 0 MPa to 509.8 MPa. Material damage area increases with the prolonging of time, and for a fixed time, material damage gradually increases from the edges to the center and reaches a constant value of 1, which means the rupture of the damage process.

scholarly journals Damage evaluation of square steel tubes at material and component levels based on a cyclic loading experiment

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879778
Author(s):  
Gui-bo Nie ◽  
Tao-yuan Yang ◽  
Xu-dong Zhi ◽  
Kun Liu
Keyword(s):  
Constitutive Model ◽  
Damage Model ◽  
Numerical Data ◽  
Material Damage ◽  
Component Level ◽  
Steel Tubes ◽  
Damage Behavior ◽  
Analysis And Design ◽  
Finite Element Software ◽  
Numerical Result

Circular and square steel tubes are two of the most commonly used members in the construction industry in China. Material damage and its accumulation cannot be neglected when structures undergo obvious deformation and material plasticity during severe earthquakes. In another published paper, a material damage constitutive model for Q235 steel was derived, and some of its parameters were defined based on a cyclic test. This article focuses on developing a normalized constitutive model at the material level and a damage model at the component level for square steel tubes based on experimentally derived results. First, the material damage behavior of 10 square steel tubes under five cyclic load schemes was investigated. The material damage and its accumulation at the material level were defined using a user-defined material sub-routine (UMAT) in the finite element software Abaqus. Next, the parameters in the constitutive model were calibrated by the fitting degree between the test result and numerical result. Furthermore, based on the experimental and numerical data, a damage model combined with deformation and energy was developed at the component level to evaluate the overall damage behavior of the specimens. Finally, the parameters in the damage model were calibrated based on the responses of the specimens at the time of collapse. The effect of material damage behavior and the accumulation of damage were found to significantly reduce the collapse load of specimens, which must be considered in the theoretical analysis and design process. The constitutive model and damage model developed in this article can be used to quantify the degree of damage of the material and components of structures under earthquake loads.

scholarly journals Numerical modeling of crack initiation and propagation processes in various specimen’s types using the GTN material damage model

2021 ◽  
Vol 5 (1) ◽  
pp. 49-56
Author(s):  
Andrew Kravchuk ◽  
Eugene Kondriakov ◽  
Valery Kharchenko
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Crack Initiation ◽  
Damage Model ◽  
Material Damage ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Crack Initiation And Propagation ◽  
Initiation And Propagation

Problematic. A combination of experimental and computational methods for studying the processes of crack initiation and propagation in various specimen’s types is used to determine the mechanical properties of materials, as well as to improve the accuracy of assessing the strength and durability of structural elements. Research objective. Determination of the parameters of the Gurson-Tvergaard-Needleman (GTN) material damage model based on the numerical modeling results of various specimen’s types under various types of loading for steel 22K using the finite element method. Realization technique. Using the finite element method, numerical modeling of the processes of cracks nucleation and propagation in cylindrical specimens under uniaxial tension, in Charpy specimens under dynamic loading, and also in CT specimens under quasi-static loading was carried out for steel 22K using the GTN material damage model. The results of research. By comparing the experimental and numerical results, the full set of GTN material model parameters for steel 22K was determined. The stress state in the crack tip area and the kinetics of its propagation in the material of various specimen’s types under static and dynamic loading were estimated. Conclusions. The GTN material damage model with the parameter values determined from experiments, can be used for numerical simulation of the processes of crack initiation and propagation both in specimens of various types under various loading types, and in structural elements.

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